1. Field of the Invention
The present invention relates to a gage inspecting apparatus and a gage inspecting method for inspecting the indication accuracy of an object to be inspected by an indicated value of the object to be inspected when a measuring spindle which is made to abut against a probe of the object to be inspected is displaced to a predetermined position. In particular, the present invention relates to a gage inspecting apparatus and a gage inspecting method excelling in operational efficiency and suitable for use in the inspection of various indicators including dial gages, lever type dial indicators, microindicators, digital type indicators, and the like.
2. Description of the Related Art
In recent years, the numbers of dial gages and the like used in manufacturing companies are on an ever-increasing trend. The reason for this is that in addition to the conventional method in which dial gages and the like are used as general-purpose comparators, cases are increases in which the dial gages or the like are used for the purpose of continuously measuring the acceptability of workpieces by attaching the dial gages to exclusive-use measuring jigs or the like.
Incidentally, in the control of dial gages and the like, inspection methods have been standardized in the International Organization for Standardization (ISO), the Japanese Industrial Standards (JIS), the American National Standards Institute (ANSI), or the Deutsche Industrie-Normen (DIN). For this reason, in conventional apparatuses for inspecting dial gages and the like, inspection methods based on ISO, JIS, ANSI or DIN standards are programmed in advance. An inspecting apparatus which makes it possible to perform the inspection of dial gages and the like in accordance with such a program has been developed (e.g., Japanese Patent Unexamined Publication No. Sho. 63-91508).
When the inspection of dial gages and the like is carried out by using such an inspecting apparatus, a measuring spindle of the inspecting apparatus is first driven to respective measurement positions. Then, readings on the gage and readings on the inspecting apparatus are inputted, andxe2x80x9cthe reading on the gage minus the reading on the inspecting apparatusxe2x80x9d at the respective measurement position is conventionally set as the indication accuracy at the corresponding measurement position.
Conventionally, however, since the micrometer head, for example, is manually moved to displace the measuring spindle, the operation has involved time and trouble. In particular, there has been a problem in that it takes time in the movement between measurement positions.
To overcome such a problem, as a semiautomatic inspection apparatus for driving the measuring. spindle by a motor, it is conceivable to automatically position the measuring spindle just short of a measurement target position by using a personal computer. However, in a case where the feeding speed of the measuring spindle is fixed irrespective of the scale interval of gages to be inspected, at the time of the spindle operation in the setup of inspection for executing the rough positioning of a reference position of measurement (an initial measurement position, e.g., a zero point) after the mounting of the gage on the inspecting apparatus, it is impossible to obtain satisfactory operational efficiency for both gages having large scale intervals and gages having small scale intervals since the scale interval of the gage is not reflected on the feeding speed of an operating button.
In addition, in a case where the moving direction of the measuring spindle is constantly set reversible irrespective of the present measuring direction (e.g., from a small value to a large value, or from a large value to a small value), there are cases where the movement in a direction opposite to the measuring direction occurs due to the erroneous operation of an operating knob. This is not allowed during the measurement during which scale adjustment to the measurement position is being effected, so as to prevent the hysteresis of the gage. Accordingly, in such a case, there has been a problem is that there are cases where the measurement must be retried from the beginning.
In addition, at the time of inspecting the indication accuracy or repetitive accuracy of the dial gage, it is necessary to drive the measuring spindle so that the hysteresis of the gage is not included in the result of measurement in accordance with the inspection standard.
To ensure that the hysteresis of the gage is not included in the result of measurement, it is sufficient to drive the measuring spindle only in a predetermined direction (which will be referred to as the measuring direction). However, when an operator adjusts the needle of the gage to the scale at a measurement target position, there are cases where the needle of the gage overshoots the scale at the measurement target position due to an operation error. In such a case, it is necessary to carry out the measurement for the relevant position once again after the measuring spindle is retracted by a distance greater than that corresponding to the value of the hysteresis of the gage. However, there have been problems in that the automatic positioning using a personal computer cannot be made use of, and that an increase in the inspection time and the operator""s fatigue are entailed.
In addition, in the case of the semiautomatic inspecting apparatus, the operator""s operation error (operation error in scale adjustment) is unavoidable, so that remeasurement for a measurement point which has been measured is required. In addition, if the result of measurement was poor, since there are cases where it is impossible to distinguish whether the poor result of measurement was due to a measurement error or the accuracy of the gage, remeasurement for the measurement point which has been measured becomes necessary for the sake of confirmation.
However, in the event that the operator is late in becoming aware that there has been a measurement error in the measurement data which has been measured, all the data need to be measured once again from the beginning by invalidating all the multiplicity of pieces of measured data. Accordingly, there has been a problem in that an increase in the inspection time and the operator""s fatigue are entailed.
Accordingly, it is a first object of the invention to provide a gage inspecting apparatus and a gage inspecting method excelling in the operational efficiency, thereby overcoming the above-described problems of the conventional art.
A second object of the invention is to facilitate the retrial of the present measurement.
A third object of the invention is to facilitate the remeasurement of the result of immediately previous measurement.
A fourth object of the invention is to facilitate the remeasurement of the result of measurement of an arbitrary point among a multiplicity of pieces of measured data.
To attain the above-described first object, a gage inspecting apparatus, in accordance with a first aspect of the invention, detects the indication accuracy of an object to be inspected on the basis of an indicated value of the object to be inspected at a time when a measuring spindle which is made to abut against a probe of the object to be inspected is displaced to a predetermined position.
The gage inspecting apparatus comprises a jog dial for controlling an amount of displacement of the measuring spindle at a time when the position of the measuring spindle is finely adjusted, and a shuttle ring for controlling the driving direction and driving speed of the measuring spindle at a time when the position of the measuring spindle is roughly adjusted.
In addition, in the above-described gage inspecting apparatus, the relationship between the amount of rotation of the jog dial and the amount of displacement of the measuring spindle can be set in correspondence with a scale interval of the gage.
In addition, in the above-described gage inspecting apparatus, the driving direction of the measuring spindle is controlled in correspondence with the direction of rotation of the shuttle ring from an intermediate position thereof, and the measuring spindle is driven at a speed proportional to an angle of rotation from the intermediate position of the shuttle ring.
In addition, in the above-described gage inspecting apparatus, there are provided a high speed mode which is independent of the scale interval of the gage and in which the measuring spindle is displaced by a large amount by a small amount of rotation of the jog dial and a maximum driving speed of the measuring spindle can be set by the shuttle ring, and a low speed mode which is dependent of the scale interval of the gage and in which the measuring spindle is displaced by a small amount by a large amount of rotation of the jog dial and the maximum driving speed of the measuring spindle cannot be set even by a maximum angle of rotation of the shuttle ring.
In addition, in the above-described gage inspecting apparatus, a changeover is freely possible between the high speed mode and the low speed mode at the time of the setup of inspection, and, during measurement, the jog dial is fixed to the low speed mode, and an instruction for displacing the jog dial in an opposite direction to a measuring direction and an instruction based on the shuttle ring are made invalid.
To attain the above-described second object, a gage inspecting apparatus, in accordance with a second aspect of the invention, detects the indication accuracy of an object to be inspected on the basis of an indicated value of the object to be inspected at a time when a measuring spindle which is made to abut against a probe of the object to be inspected is displaced to a predetermined position. The gage inspecting apparatus comprises: a retry instructing unit for instructing the retrial of the present measurement, and an automatic positioning unit which when the retrial has been instructed, causes the measuring spindle to be temporarily retracted to a position where the hysteresis of the object to be inspected can be avoided, and causes the measuring spindle to be subsequently advanced forwardly to a position located immediately in front of a present measurement target position.
To attain the above-described third object, a gage inspecting apparatus, in accordance with a third aspect of the invention, detects the indication accuracy of an object to be inspected on the basis of an indicated value of the object to be inspected at a time when a measuring spindle which is made to abut against a probe of the object to be inspected is displaced to a predetermined position. The gage inspecting apparatus comprises: a cancellation instructing unit for instructing the deletion of a result of immediately previous measurement, and an automatic positioning unit which when the cancellation has been instructed, causes the measuring spindle to be temporarily retracted to a position where the hysteresis of the object to be inspected can be avoided, and causes the measuring spindle to be subsequently advanced forwardly to a position located immediately in front of a measurement target position of an immediately previous measurement point.
To attain the above-described fourth object, a gage inspecting apparatus, in accordance with a fourth aspect of the invention, detects the indication accuracy of an object to be inspected by means of an indicated value of the object to be inspected at a time when a measuring spindle which is made to abut against a probe of the object to be inspected is displaced to a predetermined position. The gage inspecting apparatus comprises: a remeasurement instructing unit for instructing the remeasurement of a measured result of measurement, and an automatic positioning unit which when the remeasurement has been instructed, causes the measuring spindle to be temporarily retracted to a position where the hysteresis of the object to be inspected can be avoided, and causes the measuring spindle to be subsequently advanced forwardly to a position located immediately in front of a measurement target position
In addition, in the above-described gage inspecting apparatus, the retraction distance and the forwardly approaching distance by the automatic positioning unit can be designated.